CN113263436A

CN113263436A - Chemical mechanical polishing system and method of use

Info

Publication number: CN113263436A
Application number: CN202010476541.7A
Authority: CN
Inventors: 孔文彥
Original assignee: Taiji Telecom Nanjing Co ltd; Taiwan Semiconductor Manufacturing Co TSMC Ltd
Current assignee: Taiji Telecom Nanjing Co ltd; Taiwan Semiconductor Manufacturing Co TSMC Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-08-17
Anticipated expiration: 2040-05-29
Also published as: US20240009801A1; TW202145329A; US20210370466A1; CN113263436B; TWI741865B; US11724360B2

Abstract

The present disclosure relates to chemical-mechanical polishing systems and methods of use. A method of conditioning a polishing pad includes receiving information about a roughness of the polishing pad from a first sensor. The method also includes conditioning the polishing pad using a conditioner. The method also includes detecting a roughness of the polishing pad after the conditioning. The method further includes repeating the adjusting in response to the detected roughness of the polishing pad being outside a threshold roughness range.

Description

Chemical mechanical polishing system and method of use

Technical Field

The present disclosure relates to chemical-mechanical polishing systems and methods of use.

Background

Integrated circuits are formed using various process steps. Some process steps involve depositing a dielectric or metal layer on a semiconductor wafer. In some cases, the deposition process may result in a non-planar surface. The non-planar surface is polished to provide a more uniform surface for additional processing. In some cases, polishing is performed by Chemical Mechanical Polishing (CMP), which removes material from the non-planar surface to provide a more uniform surface and reduce the thickness of the semiconductor wafer.

Disclosure of Invention

According to an embodiment of the present disclosure, there is provided a method of conditioning a polishing pad, including: receiving information about the roughness of the polishing pad from a first sensor; conditioning the polishing pad using a conditioner; detecting a roughness of the polishing pad after the conditioning; and repeating the adjusting in response to the detected roughness of the polishing pad being outside a threshold roughness range.

According to another embodiment of the present disclosure, there is provided a chemical mechanical polishing CMP system including: a polishing pad configured to polish a wafer; a first sensor configured to detect a roughness of the polishing pad; a conditioner configured to adjust a roughness of the polishing pad; and a controller configured to control the conditioner based on the information received from the first sensor, wherein the controller is configured to control a number of iterations of a conditioning process performed on the polishing pad by the conditioner.

According to still another embodiment of the present disclosure, there is provided a chemical mechanical polishing CMP system including: a polishing head configured to hold a wafer during a CMP process; a polishing pad configured to polish the wafer; a plurality of sensors configured to detect a roughness of the polishing pad; a conditioner configured to adjust a roughness of the polishing pad; and a controller configured to control the regulator based on information received from the plurality of sensors, wherein the controller is configured to: controlling a number of iterations of a conditioning process performed by the conditioner on the polishing pad, controlling a position of the conditioner relative to the polishing pad, or controlling a pressure exerted by the conditioner on the polishing pad.

Drawings

Various aspects of this disclosure may be best understood from the following detailed description when read in conjunction with the accompanying drawings. It is noted that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is an illustration of a Chemical Mechanical Polishing (CMP) system in accordance with one or more embodiments.

FIG. 2 is a flow diagram of a method of using a CMP system in accordance with one or more embodiments.

Figure 3 is a block diagram of a computing device for controlling a CMP system in accordance with one or more embodiments.

Figures 4A and 4B are cross-sectional views of a polishing pad and a wafer in accordance with one or more embodiments.

Detailed Description

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. Other components, values, operations, materials, arrangements, etc. are contemplated. For example, in the description below, forming a first feature over or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. Further, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Furthermore, spatially relative terms, such as "under," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Chemical Mechanical Polishing (CMP) is used to planarize the surface of semiconductor devices during processing. Ideally, after the CMP process, the surface of the semiconductor device is completely flat. However, during the manufacturing process, a number of factors affect the performance of the CMP process. One of these factors is the roughness of the polishing pad. The roughness of the polishing pad will have an effect on the polishing performance of the CMP process. The pattern density is the density of features on the wafer surface. As the number of features per unit area increases, the pattern density also increases. In some cases, when the roughness of the polishing pad is reduced below a threshold range, the ratio of the thickness of the low density region to the thickness of the high density region is reduced to less than a target range. For example, FIG. 4B includes a polishing pad having a roughness below a threshold range. In contrast, in some cases, when the roughness of the polishing pad increases above a threshold range, the ratio of the thickness of the low-density region to the thickness of the high-density region increases above a target range. For example, FIG. 4A includes a polishing pad having a roughness above a threshold range. That is, a polishing pad having a surface roughness outside of a threshold range causes thickness variations on the wafer depending on the locations of the high pattern density region and the low pattern density region.

According to some embodiments of the present description, monitoring the roughness of the polishing pad and controlling the polishing pad conditioning process helps to reduce or avoid thickness variations on the wafer by controlling the polishing pad roughness within a threshold range. In some embodiments, the number of iterations of the conditioning process is controlled to assist in managing polishing pad roughness. In some embodiments, the number of conditioning pads used in the conditioning process is controlled to assist in managing polishing pad roughness. In some embodiments, the control adjusts the pressure or position of the pad to assist in managing polishing pad roughness. The roughness of the polishing pad is maintained within a threshold range by controlling the conditioning process.

As the polishing pad continues to polish the wafer, the polishing pad eventually degrades to the point where the polishing pad can no longer recover to a roughness within the threshold range. If the polishing pad is replaced too frequently, the manufacturing costs increase because the available polishing pad is replaced prematurely. In contrast, if the polishing pad is replaced too late, a wafer that is subjected to a CMP process using the polishing pad that should be replaced will have increased thickness variation. As a result, the probability of failure of devices formed on the wafer increases. In some embodiments, the controller is used to determine when to replace the polishing pad to help reduce manufacturing costs and reduce the risk of faulty devices on the wafer.

CMP systems use a combination of chemical reaction and mechanical polishing to remove material from the surface of a semiconductor device. FIG. 1 is a diagram of a CMP system 100 according to one or more embodiments. The CMP system 100 includes a platen 102 configured to rotate in at least one direction. A polishing pad 104 is disposed on top of the platen 102. The polishing head 106 is configured to support a wafer for processing using the CMP system 100. The polishing head 106 is configured to adjust the pressure exerted by the polishing pad 104 on the wafer. The CMP system 100 also includes a conditioner 108, the conditioner 108 configured to restore the roughness of the polishing pad 104. The CMP system 100 also includes a slurry delivery system 110, the slurry delivery system 110 being configured to deliver slurry to the polishing pad 104 to facilitate removal of material from the wafer. The sensor 115 is used to monitor the roughness of the polishing pad 104. In some embodiments, optional sensor 117 is configured to receive light reflected from sensor 115. The controller 120 is configured to receive information from the sensor 115 or the sensor 117 and to control the regulator 108 based on the received information.

The CMP system 100 removes material from the wafer based on the relative motion between the polishing pad 104 and the polishing head 106. The slurry introduced into the polishing pad 104 by the slurry delivery system 110 reacts with material on the wafer and the mechanical force exerted by the polishing pad on the wafer removes material from the wafer.

The platen 102 is configured to rotate in at least a first direction. In some embodiments, the platen 102 is configured to rotate in more than one direction. In some embodiments, the platen 102 is configured to remain stationary. In some embodiments, the platen 102 is configured to have a constant rotational speed. In some embodiments, the platen 102 is configured to have a variable rotational speed. In some embodiments, the pressure plate 102 is rotated by the engine. In some embodiments, the engine is an Alternating Current (AC) engine, a Direct Current (DC) engine, a general purpose engine, or another suitable engine. In some embodiments, the platen 102 is configured to translate in one or more directions.

The platen 102 is configured to support a polishing pad 104. The polishing pad 104 is configured to be coupled to the platen 102 such that the polishing pad 104 rotates in the same direction at the same speed as the platen. In some embodiments where the platen 102 is stationary, the polishing pad 104 remains stationary. The polishing pad 104 has a textured surface configured to remove material from the wafer during operation of the CMP system 100.

The polishing head 106 is configured to support a wafer during operation of the CMP system 100. In some embodiments, the polishing head 106 includes a retaining ring for securing the wafer against the polishing head. In some embodiments, the polishing head 106 includes a vacuum to hold the wafer against the polishing head. The polishing head 106 is configured to rotate in a second direction. In some embodiments, the second direction is the same as the first direction. In some embodiments, the second direction is opposite the first direction. In some embodiments, the polishing head 106 is configured to rotate at a constant rotational speed. In some embodiments, the polishing head 106 is configured to rotate at a variable rotational speed. In some embodiments, the buffing head 106 is rotated by a motor. In some embodiments, the engine is an AC engine, a DC engine, a general purpose engine, or another suitable engine. In some embodiments, the polishing head 106 remains stationary. In some embodiments, the polishing head 106 translates relative to the polishing pad 104.

The polishing head 106 is configured to move in a direction perpendicular to the surface of the polishing pad 104. By moving the polishing head 106 in a direction perpendicular to the surface of the polishing pad 104, the pressure exerted by the polishing pad on the wafer is adjustable. In some embodiments, the polishing head 106 includes a pressure sensor for monitoring the pressure exerted on the wafer. In some embodiments, the pressure sensor is connected to the control system. In some embodiments, the polishing head 106 includes a pressure adjustment device configured to apply a force on a surface of the wafer opposite the polishing pad 104 to adjust the pressure applied on the wafer at different locations of the wafer. In some embodiments, the pressure adjustment device includes a nozzle configured to emit pressurized gas, a movable latch, or other suitable force-applying element.

The conditioner 108 is configured to restore the roughness of the polishing pad 104. During operation of the CMP system 100, the roughness of the polishing pad 104 is reduced due to forces between the wafer and the polishing pad or by the accumulation of slurry or other particles. The conditioner 108 is configured to restore the roughness of the polishing pad 104 to maintain efficient operation of the CMP system 100.

The conditioner 108 includes a conditioner pad 108a, and the conditioner pad 108a is configured to contact the polishing pad 104. In some embodiments, the adjuster pad 108a is configured to rotate. The conditioner 108 further includes a conditioner arm 108b, the conditioner arm 108b configured to translate the conditioner pad 108a over the surface of the polishing pad 104.

The slurry delivery system 110 is configured to provide a slurry onto the polishing pad 104. In some embodiments, the slurry delivery system 110 includes a slurry mixing system configured to mix the various fluid components prior to delivering the mixture to the polishing pad 104. The slurry delivery system 110 includes at least one nozzle 110a, the at least one nozzle 110a configured to deliver the slurry to the polishing pad 104. The slurry delivery system 110 also includes a delivery arm 110b, the delivery arm 110b configured to translate the position of the nozzle 110a relative to the surface of the polishing pad 104.

The sensor 115 is configured to collect information related to the roughness of the polishing pad 104. For simplicity, a single sensor 115 is included in FIG. 1. In some embodiments, multiple sensors 115 are included to detect roughness at different locations on the polishing pad 104. In some embodiments, the sensor 115 is an integrated array of sensing elements extending across a portion of the polishing pad 104. By collecting information about the roughness at different locations, the sensor 115 will be able to more accurately locate portions of the polishing pad 104 having a roughness outside of a threshold range. In some embodiments, the sensor 115 is an optical sensor configured to receive light reflected from the surface of the polishing pad 104. In some embodiments, the sensor 115 is sensitive to visible light. In some embodiments, the sensor 115 is sensitive to Infrared (IR) light. In some embodiments, each sensor 115 of the plurality of sensors 115 is the same type of sensor, such as a visible light detection sensor. In some embodiments, at least one sensor 115 of the plurality of sensors 115 is different from another sensor 115, e.g., one sensor 115 is sensitive to visible light and one sensor 115 is sensitive to IR light. In some embodiments, the sensor 115 is configured to emit light toward the polishing pad 104.

The sensor 117 is configured to receive light originating from the sensor 115 that is reflected by the polishing pad 104. For simplicity, a single sensor 117 is included in FIG. 1. In some embodiments, a plurality of sensors 117 are included to detect roughness at different locations on the polishing pad 104. In some embodiments, the sensor 117 is an integrated array of sensing elements extending across a portion of the polishing pad 104. By collecting information about the roughness at different locations, the sensor 117 will be able to more accurately locate portions of the polishing pad 104 having a roughness outside of a threshold range. In some embodiments, each sensor 115 is paired with a sensor 117. In some embodiments, at least one sensor 115 is a stand-alone sensor that is not paired with sensor 117. In some embodiments, the sensor 117 is an optical sensor configured to receive light reflected from the surface of the polishing pad 104. In some embodiments, the sensor 117 is sensitive to visible light. In some embodiments, the sensor 117 is sensitive to IR light. In some embodiments, each sensor 117 of the plurality of sensors 117 is the same type of sensor, such as a visible light detection sensor. In some embodiments, at least one sensor 117 of the plurality of sensors 117 is different from another sensor 117, e.g., one sensor 117 is sensitive to visible light and one sensor 117 is sensitive to IR light. In some embodiments, the sensors 117 are omitted, wherein each sensor 115 is a separate sensor.

The polishing pad 104 has a radius R extending from the center of the platen to the outer edge of the platen. In some embodiments, the radius R of the polishing pad 104 is at least 2.5 times the radius of the polishing head 106. In some embodiments, if the radius R of the polishing pad 104 is less than 2.5 times the radius of the polishing head 106, it is difficult to maintain the roughness of the polishing pad, which increases polishing time and decreases throughput.

As the polishing pad 104 and polishing head 106 rotate, the position of the detection point(s) of the sensor 115 and/or sensor 117 relative to the polishing pad 104 changes. By using multiple different detection points, a more uniform amount of data is collected relating to each area on the polishing pad 104. The uniform amount of data enables a more accurate determination of the roughness profile of the polishing pad 104. The roughness profile is a variation in roughness across the surface of the polishing pad 104. For example, in some embodiments, in some cases, the region of the polishing pad 104 most commonly used during a CMP process will have the lowest roughness

The controller 120 is configured to receive information from the sensor 115. In some embodiments including sensor 117, controller 120 is configured to receive information from sensor 117. In some embodiments, the information includes an image of the polishing pad 104. In some embodiments, the information includes a signal indicative of the roughness of the polishing pad 104. The controller 120 is configured to determine the roughness of the polishing pad 104 based on the received information. In some embodiments including a plurality of sensors 115 and/or sensors 117, the controller 120 is configured to determine a roughness profile of the polishing pad 104.

Based on information from the sensor 115 or the sensor 117 for the polishing pad 104, the controller 120 is configured to control the conditioner 108. In some embodiments, the controller 120 controls the number of iterations of the conditioning process of the conditioner 108. The controller 120 is also configured to track iterations of the conditioning process used on the polishing pad 104. In some embodiments, the controller 120 is configured to adjust the pressure of the conditioner head 108a on the polishing pad 104. In some embodiments, the controller 120 is configured to adjust the position of the conditioner head 108a based on the determined roughness profile of the polishing pad 104. In some embodiments, the controller 120 is configured to control a secondary conditioner (not shown) to increase the number of conditioners used to adjust the roughness of the polishing pad 104.

FIG. 2 is a flow diagram of a method 200 of using a CMP system in accordance with one or more embodiments. In operation 202, a wafer is attached to a polishing head. In some embodiments, the wafer is attached to the polishing head 106 (fig. 1). In some embodiments, the wafer is attached to the polishing head using a retaining ring. In some embodiments, the wafer is attached to the polishing head using a vacuum or other suitable attachment element. In some embodiments, operation 202 is omitted. For example, when operation 202 is implemented by a user or another device, the operation is omitted.

In operation 204, a CMP process is initiated. The CMP process involves applying pressure to the wafer against a polishing pad. In some embodiments, the wafer is rotated relative to the polishing pad. In some embodiments, the polishing pad is rotated relative to the wafer. In some embodiments, both the wafer and the polishing pad are rotated. The CMP process also includes applying the slurry to the polishing pad and conditioning the polishing pad to restore the texture of the polishing pad. In some embodiments, the wafer is configured to translate relative to the polishing pad. In some embodiments, the polishing pad is configured to translate relative to the wafer. In some embodiments, operation 204 is omitted. For example, when operation 204 is implemented by a user or another device, the operation is omitted.

In step 206, the polishing pad is monitored for roughness. In some embodiments, a single detection point is used to monitor the roughness of the polishing pad. In some embodiments, the roughness of the polishing pad is monitored using a plurality of detection points. In some embodiments, the roughness of the polish is monitored using sensor 115 and/or sensor 117 (FIG. 1). In some embodiments, a plurality of detection points are used to monitor the roughness profile of the polishing pad. In some embodiments, the roughness of the polishing pad is monitored using the reflected beam.

In step 208, the conditioner of the CMP system is controlled to adjust the roughness of the polishing pad. In some embodiments, the number of iterations of the conditioning process is adjusted based on information received from sensors (e.g., sensor 115 and/or sensor 117 (fig. 1)). In some embodiments, the position of the regulator head (e.g., regulator head 108a) is adjusted based on information from a sensor (e.g., sensor 115 and/or sensor 117 (fig. 1)). In some embodiments, the pressure of the regulator head (e.g., regulator head 108a) is adjusted based on information received from the sensor (e.g., sensor 115 and/or sensor 117 (fig. 1)). In some embodiments, a smoothing conditioner is used to reduce the roughness of the polishing pad. In some embodiments, the pressure of the conditioner head is adjusted by moving the conditioner head in a direction perpendicular to the polishing pad. In some embodiments, the movement of the conditioner head occurs during the CMP process. In some embodiments, the movement of the conditioner head occurs after the CMP process. In some embodiments, the conditioner is adjusted to provide a uniform distribution over the polishing surface of the wafer. In some embodiments, additional conditioner heads are used during the conditioning process. In some embodiments, the additional regulator head helps to reduce the amount of time to complete the conditioning process. In some embodiments, the additional conditioner heads help to account for variations in roughness distribution in the polishing pad

In operation 210, the roughness of the polishing pad is compared to a threshold roughness range. In some embodiments, the threshold roughness range is selected by a user. In some embodiments, the threshold roughness range is determined based on empirical data related to the performance of the CMP process. In some embodiments, roughness information is collected after the conditioning process to compare to a threshold roughness range. In some embodiments, roughness information is collected during the conditioning process. In some embodiments, the roughness is measured at a single location on the polishing pad. In some embodiments, the roughness is measured at a plurality of locations on the polishing pad.

The method 200 returns to operation 202 in response to the roughness of the polishing pad satisfying the threshold roughness range. In some embodiments, a new wafer is placed on the polishing head in response to the method 200 returning to operation 202. In some embodiments, in response to the method 200 returning to operation 202, the same wafer on the polishing head undergoes an additional CMP process. The decision as to whether to place a new wafer on the polishing head is based on whether the desired thickness of the polished wafer is achieved. The method 200 proceeds to operation 212 in response to the roughness of the polishing pad not satisfying the threshold roughness range. In some embodiments, if the roughness at any single location on the polishing pad does not meet the threshold roughness range, the method 200 proceeds to operation 212. In some embodiments, if the roughness of the first location on the polishing pad does not satisfy the threshold roughness range, but the second location satisfies the threshold roughness range, then additional iterations of adjustment are performed only for the unsatisfied locations of the polishing pad.

In operation 212, the number of iterations of the adjustment process is compared to an iteration limit. In some embodiments, the iterations are limited to between about 3 and about 5 iterations. If the iteration limit is too low, the polishing pad may be replaced more frequently, which may increase production costs in some cases. If the iteration limit is too high, additional time may be spent attempting to increase the roughness of the polishing pad, thereby reducing the production yield of the manufacturing process. In some embodiments, the number of iterations is adjusted in response to a conditioning process that includes a plurality of conditioners. For example, in some embodiments, if two regulators are used in the regulation process, the number of iterations of the regulation process is increased twice instead of once. In some embodiments, the number of iterations of the conditioning process is determined without regard to the number of conditioners used in the conditioning process. The method 200 returns to operation 206 in response to the number of iterations being less than the iteration limit. The method 200 proceeds to operation 214 in response to the number of iterations reaching an iteration limit.

In operation 214, the CMP process is stopped. In some embodiments, the CMP process is stopped based on the wafer thickness reaching a target thickness. In some embodiments, the CMP process is stopped based on the duration of the CMP process reaching the target duration. In some embodiments, the CMP process is stopped based on the roughness of the polishing pad not being able to be performed properly.

In operation 216, the polishing pad is replaced. In some embodiments, the user is notified and instructed to replace the polishing pad. In some embodiments, the control signal is sent to an automated system for changing polishing pads; and the automated system replaces the polishing pad without user interaction.

In some embodiments, prior to the operation, at least one operation is included in method 200. For example, in some embodiments, an initial polishing pad is attached to the platen prior to operation 202. In some embodiments, at least one operation is performed after the operation. For example, in some embodiments, the conditioner is replaced after the polishing pad is replaced. In some embodiments, at least one operation from method 200 is omitted. For example, in some embodiments, operation 202 is omitted, as described above. In some embodiments, the order of the operations of method 200 is changed. For example, in some embodiments, operation 208 is performed before operation 206. In some embodiments, when operation 208 is performed before operation 206, a default conditioning process is performed in a first iteration, and the conditioning process is adjusted in a subsequent iteration based on the detected roughness of the polishing pad.

FIG. 3 is a block diagram of a computing device 300 for controlling a CMP system in accordance with one or more embodiments. The computing device 300 includes a hardware processor 302 and a non-transitory computer-readable storage medium 304, the non-transitory computer-readable storage medium 304 being encoded with (i.e., storing) computer program code 306 (i.e., a set of executable instructions). The computer-readable storage medium 304 is also encoded with instructions 307 for interfacing with elements of the CMP system 100. The processor 302 is electrically coupled to the computer-readable storage medium 304 via a bus 308. Processor 302 is also electrically coupled to I/O interface 310 via bus 308. A network interface 312 is also electrically connected to the processor 302 via the bus 308. The network interface 312 is connected to a network 314, so that the processor 302 and the computer-readable storage medium 304 can be connected to external elements via the network 314. The processor 302 is configured to execute computer program code 306 encoded in a computer readable storage medium 304 to make the computing apparatus 300 operable to perform some or all of the operations described with respect to the CMP system 100.

In some embodiments, processor 302 is a Central Processing Unit (CPU), multiprocessor, distributed processing system, Application Specific Integrated Circuit (ASIC), and/or suitable processing unit.

In some embodiments, the computer-readable storage medium 304 is an electronic, magnetic, optical, electromagnetic, infrared, and/or semiconductor system (or apparatus or device). The computer-readable storage medium 304 includes, for example, a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a Random Access Memory (RAM), a read-only memory (ROM), a rigid magnetic disk and/or an optical disk. In some embodiments using optical disks, computer-readable storage medium 304 includes compact disk read-only memory (CD-ROM), compact disk read/write (CD-R/W), and/or Digital Video Disk (DVD).

In some embodiments, the storage medium 304 stores computer program code 306, the computer program code 306 configured to cause the computing device 300 to perform the operations described with respect to the CMP system 100. In some embodiments, the storage medium 304 also stores information needed to perform operations described with respect to the CMP system 100, such as a sensor parameter 316, an adjustment iteration parameter 318, an adjuster pressure parameter 320, a target roughness parameter 322, and/or a set of execution instructions for performing operations described with respect to the CMP system 100.

In some embodiments, the storage medium 304 stores instructions 307 for interfacing with the CMP system 100. The instructions 307 enable the processor 302 to generate operational instructions readable by elements of the CMP system 100 to effectively implement the operations described with respect to the CMP system 100.

Computer device 300 includes I/O interface 310. The I/O interface 310 is coupled to external circuitry. In some embodiments, the I/O interface 310 includes a keyboard, buttons, a mouse, a trackball, a trackpad, and/or cursor direction keys for communicating information and commands to the processor 302.

The computing device 300 also includes a network interface 312 coupled to the processor 302. Network interface 312 allows computing device 300 to communicate with a network 314, to which one or more other computer systems are connected. The network interface 312 includes: wireless network interfaces such as bluetooth, WIFI, WIMAX, GPRS, or WCDMA; or a wired network interface such as ethernet, USB, or IEEE-1394. In some embodiments, the operations described with respect to the CMP system 100 are implemented in two or more computing devices 300, and information such as sensor information, conditioning iteration information, conditioner pressure, and target roughness is exchanged between the different computing devices 300 via the network 314.

Computing device 300 is configured to receive information related to sensors (e.g., sensor 115 and/or sensor 117 (fig. 1)) through I/O interface 310. This information is transmitted to the processor 302 via bus 308 to determine the roughness of the polishing pad at the sensor location. The roughness and/or profile is then stored as sensor parameters 316 in the computer-readable medium 304. Computing device 300 is configured to receive information related to tuning iterations through I/O interface 310. This information is communicated to the processor 302 via bus 308 to determine the number of adjustment iterations. The number of adjustment iterations is then stored in the computer-readable medium 304 as an adjustment iteration parameter 318. The computing device 300 is configured to receive information related to regulator pressure via the I/O interface 310. In some embodiments, the pressure information is provided by a pressure sensor located in the regulator head. This information is stored in the computer readable medium 304 as the regulator pressure parameter 320. Computing device 300 is configured to receive information related to a target roughness through I/O interface 310. In some embodiments, target roughness information is received from an operator. In some embodiments, the target roughness is calculated based on information related to the manufacturing process received by the computing apparatus 300. This information is stored in the computer-readable medium 304 as target roughness parameters 322.

During operation, in some embodiments, processor 302 executes a set of instructions to determine whether to perform another iteration of the conditioning process using the conditioner based on sensor parameters 316, conditioning iteration parameters 318, and target roughness parameters 322. During operation, the processor 302 executes a set of instructions to determine whether the roughness of the polishing pad is within a threshold range based on the sensor parameters 316 and the target roughness parameter 322. Based on the determination, the processor 302 generates a control signal to instruct the regulator to perform another regulation process. In some embodiments, the control signals are sent using the I/O interface 310. In some embodiments, the control signal is sent using the network interface 312.

During operation, in some embodiments, processor 302 executes a set of instructions to determine whether to adjust the pressure of the regulator based on sensor parameters 316, regulator pressure parameters 320, and target roughness parameters 322. During operation, the processor 302 executes a set of instructions to determine whether the roughness of the polishing pad is within a threshold range based on the sensor parameters 316 and the target roughness parameter 322. Based on the determination, the processor 302 generates a pressure adjustment signal to adjust the position of the regulator head. In some embodiments, the pressure adjustment signal is sent using the I/O interface 310. In some embodiments, the pressure adjustment signal is sent using the network interface 312.

During operation, in some embodiments, processor 302 executes a set of instructions to determine whether to adjust the position of the conditioner based on sensor parameters 316 and target roughness parameters 322. During operation, the processor 302 executes a set of instructions to determine whether the roughness of the polishing pad is within a threshold range at various locations on the polishing pad based on the sensor parameters 316 and the target roughness parameters 322. Based on the above determination, the processor 302 generates a conditioner position adjustment signal to adjust the position of the conditioner head on the polishing pad. The position of the conditioner head is adjustable in a direction perpendicular to the polishing pad to adjust the pressure applied to the polishing pad; or may be adjusted in a direction parallel to the top surface of the polishing pad to adjust different areas of the polishing pad. In some embodiments, the regulator position adjustment signal is sent using the I/O interface 310. In some embodiments, the regulator position adjustment signal is sent using the network interface 312.

One aspect of the present description relates to a method of conditioning a polishing pad. The method includes receiving information about the roughness of the polishing pad from a first sensor. The method also includes conditioning the polishing pad using the conditioner. The method also includes detecting a roughness of the polishing pad after conditioning. The method further includes repeating the adjusting in response to the detected roughness of the polishing pad being outside of a threshold roughness range. In some embodiments, the method further comprises tracking a number of iterations of the adjustment; and outputting a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit. In some embodiments, the method further comprises receiving information about the roughness of the polishing pad from a second sensor, wherein the second sensor is configured to detect the roughness at a different location than the first sensor; and determining a roughness profile of the polishing pad based on the information received from the first sensor and the second sensor. In some embodiments, the method further comprises adjusting a position of the conditioner relative to the polishing pad based on the determined roughness profile. In some embodiments, adjusting the position of the conditioner includes moving the conditioner in a direction parallel to the top surface of the polishing pad. In some embodiments, the method further comprises adjusting the pressure applied by the conditioner on the polishing pad based on information received from the first sensor. In some embodiments, adjusting the pressure comprises moving the conditioner in a direction perpendicular to the top surface of the polishing pad. In some embodiments, conditioning the polishing pad includes conditioning the polishing pad during a Chemical Mechanical Polishing (CMP) process. In some embodiments, conditioning the polishing pad includes conditioning the polishing pad after the CMP process. In some embodiments, receiving information about roughness includes receiving information about roughness during a CMP process.

One aspect of the present description relates to a Chemical Mechanical Polishing (CMP) system. The CMP system includes a polishing pad configured to polish a wafer. The CMP system also includes a first sensor configured to detect a roughness of the polishing pad. The CMP system also includes a conditioner configured to adjust a roughness of the polishing pad. The CMP system also includes a controller configured to control the conditioner based on the information received from the first sensor, wherein the controller is configured to control a number of iterations of a conditioning process performed by the conditioner on the polishing pad. In some embodiments, the first sensor is an optical sensor. In some embodiments, the CMP system further comprises a second sensor configured to detect the roughness of the polishing pad, wherein the second sensor is located above a different portion of the polishing pad than the first sensor. In some embodiments, the controller is configured to determine a roughness profile of the polishing pad based on information from the first sensor and from the second sensor. In some embodiments, the controller is configured to control the conditioner based on the determined roughness profile. In some embodiments, the controller is configured to control a position of the conditioner relative to the polishing pad based on the determined roughness profile. In some embodiments, the controller is configured to control the pressure applied by the conditioner on the polishing pad based on information received from the first sensor. In some embodiments, the controller is configured to track a number of iterations of the conditioning process.

One aspect of the present description relates to a Chemical Mechanical Polishing (CMP) system. The CMP system includes a polishing head configured to hold a wafer during a CMP process. The CMP system includes a polishing pad configured to polish a wafer. The CMP system also includes a plurality of sensors configured to detect a roughness of the polishing pad. The CMP system also includes a conditioner configured to adjust the roughness of the polishing pad. The CMP system also includes a controller configured to control the conditioner based on information received from the plurality of sensors. The controller is configured to control a number of iterations of a conditioning process performed by the conditioner on the polishing pad, to control a position of the conditioner relative to the polishing pad, or to control a pressure exerted by the conditioner on the polishing pad. In some embodiments, a first sensor of the plurality of sensors is configured to emit light toward the polishing pad and a second sensor of the plurality of sensors is configured to receive the emitted light reflected from the polishing pad.

The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the various aspects of the disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Example 1. a method of conditioning a polishing pad, comprising: receiving information about the roughness of the polishing pad from a first sensor; conditioning the polishing pad using a conditioner; detecting a roughness of the polishing pad after the conditioning; and repeating the adjusting in response to the detected roughness of the polishing pad being outside a threshold roughness range.

Example 2. the method of example 1, further comprising: tracking the number of iterations of the adjustment; and outputting a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit.

Example 3. the method of example 1, further comprising: receiving information about a roughness of the polishing pad from a second sensor, wherein the second sensor is configured to detect the roughness at a different location than the first sensor; and determining a roughness profile of the polishing pad based on information received from the first sensor and the second sensor.

Example 4. the method of example 3, further comprising: adjusting a position of the conditioner relative to the polishing pad based on the determined roughness profile.

Example 5. the method of example 4, wherein adjusting the position of the adjuster comprises: moving the conditioner in a direction parallel to a top surface of the polishing pad.

Example 6. the method of example 1, further comprising: adjusting the pressure exerted by the conditioner on the polishing pad based on the information received from the first sensor.

Example 7. the method of example 6, wherein adjusting the pressure comprises: moving the conditioner in a direction perpendicular to the top surface of the polishing pad.

Example 8. the method of example 1, wherein conditioning the polishing pad comprises: conditioning the polishing pad during a Chemical Mechanical Polishing (CMP) process.

Example 9. the method of example 1, wherein conditioning the polishing pad comprises: conditioning the polishing pad after the CMP process.

Example 10 the method of example 1, wherein receiving information about the roughness comprises: information regarding the roughness is received during a CMP process.

Example 11. a chemical mechanical polishing, CMP, system, comprising: a polishing pad configured to polish a wafer; a first sensor configured to detect a roughness of the polishing pad; a conditioner configured to adjust a roughness of the polishing pad; and a controller configured to control the conditioner based on the information received from the first sensor, wherein the controller is configured to control a number of iterations of a conditioning process performed on the polishing pad by the conditioner.

Example 12. the CMP system of example 11, wherein the first sensor is an optical sensor.

Example 13. the CMP system of example 11, further comprising: a second sensor configured to detect a roughness of the polishing pad, wherein the second sensor is located above a different portion of the polishing pad than the first sensor.

Example 14. the CMP system of example 13, wherein the controller is configured to determine the roughness profile of the polishing pad based on information from the first sensor and from the second sensor.

Example 15 the CMP system of example 14, wherein the controller is configured to control the conditioner based on the determined roughness profile.

Example 16. the CMP system of example 15, wherein the controller is configured to control a position of the conditioner relative to the polishing pad based on the determined roughness profile.

Example 17. the CMP system of example 11, wherein the controller is configured to control the pressure exerted by the conditioner on the polishing pad based on information received from the first sensor.

Example 18. the CMP system of example 11, wherein the controller is configured to track a number of iterations of the conditioning process.

Example 19. a chemical mechanical polishing, CMP, system, comprising: a polishing head configured to hold a wafer during a CMP process; a polishing pad configured to polish the wafer; a plurality of sensors configured to detect a roughness of the polishing pad; a conditioner configured to adjust a roughness of the polishing pad; and a controller configured to control the regulator based on information received from the plurality of sensors, wherein the controller is configured to: controlling a number of iterations of a conditioning process performed by the conditioner on the polishing pad, controlling a position of the conditioner relative to the polishing pad, or controlling a pressure exerted by the conditioner on the polishing pad.

Example 20 the CMP system of example 19, wherein a first sensor of the plurality of sensors is configured to emit light toward the polishing pad and a second sensor of the plurality of sensors is configured to receive emitted light reflected from the polishing pad.

Claims

1. A method of conditioning a polishing pad comprising:

receiving information about the roughness of the polishing pad from a first sensor;

conditioning the polishing pad using a conditioner;

detecting a roughness of the polishing pad after the conditioning; and

repeating the adjusting in response to the detected roughness of the polishing pad being outside a threshold roughness range.

2. The method of claim 1, further comprising:

tracking the number of iterations of the adjustment; and

outputting a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit.

3. The method of claim 1, further comprising:

receiving information about a roughness of the polishing pad from a second sensor, wherein the second sensor is configured to detect the roughness at a different location than the first sensor; and

determining a roughness profile of the polishing pad based on information received from the first sensor and the second sensor.

4. The method of claim 3, further comprising: adjusting a position of the conditioner relative to the polishing pad based on the determined roughness profile.

5. The method of claim 4, wherein adjusting the position of the regulator comprises: moving the conditioner in a direction parallel to a top surface of the polishing pad.

6. The method of claim 1, further comprising: adjusting the pressure exerted by the conditioner on the polishing pad based on the information received from the first sensor.

7. The method of claim 6, wherein adjusting the pressure comprises: moving the conditioner in a direction perpendicular to the top surface of the polishing pad.

8. The method of claim 1, wherein conditioning the polishing pad comprises: conditioning the polishing pad during a Chemical Mechanical Polishing (CMP) process.

9. A chemical mechanical polishing CMP system, comprising:

a polishing pad configured to polish a wafer;

a first sensor configured to detect a roughness of the polishing pad;

a conditioner configured to adjust a roughness of the polishing pad; and

a controller configured to control the conditioner based on the information received from the first sensor, wherein the controller is configured to control a number of iterations of a conditioning process performed on the polishing pad by the conditioner.

10. A chemical mechanical polishing CMP system, comprising:

a polishing head configured to hold a wafer during a CMP process;

a polishing pad configured to polish the wafer;

a plurality of sensors configured to detect a roughness of the polishing pad;

a conditioner configured to adjust a roughness of the polishing pad; and

a controller configured to control the regulator based on information received from the plurality of sensors, wherein the controller is configured to:

controlling a number of iterations of a conditioning process performed by the conditioner on the polishing pad,

controlling the position of the conditioner relative to the polishing pad, or

Controlling the pressure exerted by the conditioner on the polishing pad.